1. Field of the Invention
The present invention relates to a pharmaceutical preparation containing an NFκB decoy oligonucleotide that binds to NFκB.
2. Description of the Related Art
Recently, all base sequences of a human genome have been decoded, and it has become clarified that various diseases may be caused by genetic disorders, and in future, the relationship between more diseases and genes may be clarified. Based on these information, so-called Gene Therapy which enables various diseases caused by genetic disorders to be treated fundamentally at genetic level is now strongly anticipated as a new therapeutic strategy for intractable diseases.
For example, it is suggested that most of various diseases such as asthma, cancer, cardiac disease, aneurysm, autoimmune disease, viral infection, though individually exhibiting different symptoms, may be caused by abnormal expression (over-expression or under-expression) of one or a few proteins. In general, the protein expression is controlled by various transcriptional regulators such as transcriptional activators and transcriptional suppressors.
NFκB is a transcriptional regulator comprising p65 and p50 heterodimers. In general, NFκB exists in a cytoplasm as a form with its inhibitor IκB bonding thereto, and its nuclear import is thereby inhibited. However, when some stimulation such as cytokine, ischemia or reperfusion is given thereto for some reasons, IκB may be decomposed through phosphorylation and NFκB may be thereby activated, resulting in its nuclear import. The nuclear-imported NFκB binds to the NFκB-binding region on a genome, and promotes the transcription of the gene existing at its downstream. Some genes existing at the downstream of the NFκB-binding site are known, including, for example, inflammatory cytokines such as IL-1, IL-6, IL-8, tumor necrosis factor α (TNFα), and adhesion factors such as VCAM-1, ICAM-1.
Some reasons for atopic dermatitis, a type of intractable skin diseases may be taken into consideration, including environmental factors such as allergen, environmental pollution, pollen, stress, and genetic factors such as over-immune system, skin barrier disorder; and these factors may act compositely and the water-holding function and the barrier function of the skin horny layer (corneal layer of epidermis, stratum corneum epidermidis) may lower thereby resulting in that allergens and stimulants may invade the inside of the skin to cause irritation and itching. In addition, after repeatedly scratched, the skin horny layer may be damaged and allergens and stimulants may more readily invade the inside of the skin; and the vicious circle is repeated.
It is known that, in a pathology of atopic dermatitis or a model animal with atopic dermatitis, activation of NFκB induces expression of inflammation-related gene groups (e.g., cytokine, chemokine, adhesion factor) that accompany invasion or activation of lymphocytes, therefore playing an important role in disease onset and development. In addition, it is suggested that the activation of NFκB is an important mechanism also in skin diseases such as psoriasis vulgaris, contact dermatitis.
Recently, studies of administering an NFκB decoy oligodeoxynucleotide (hereinafter referred to as “NFκB decoy”) capable of inhibiting the formation of cytokines and others that bind to NFκB to cause inflammations, thereby fundamentally removing causes of disease for atopic dermatitis and others, have been made actively.
For example, Patent References 1 to 3 disclose an ointment preparation for treatment of skin diseases such as atopic dermatitis, containing an NFκB decoy. Patent Reference 4 discloses a method of using a liposome as a carrier (vector) of NFκB decoy. Further, Patent Reference 5 discloses a method of incorporating a nucleic acid drug in folic acid-modified nanoparticles thereby increasing the intracellular transportation of the drug.
However, the NFκB decoy has an extremely large molecular weight of about 12,000; and according to the methods of Patent References 1 to 3, its skin permeability is low in a site eroded by scratching or except a facial site having a relatively low barrier function, and therefore it could not be transported to the inside of the cells in affected sites. Accordingly, at those sites having a high barrier function, the NFκB decoy could not sufficiently exhibit its therapeutical effect; and it is desired to further improve the skin permeability and the intracellular transportability of the NFκB decoy. In the method of Patent Reference 4, the liposome is a phospholipid and is highly safe to human bodies, but on the other hand, the method is insufficient in point of the efficiency and the effect of the NFκB decoy introduction and the sustainability thereof. Further, the method of Patent Reference 5 is problematic in that it requires an additional step of preparing folic acid-polyethylene glycol-distearoylphosphatidylethanolamine that is to be the starting material for the folic-acid modified nanoparticles, and the number of the constitutive steps of the method increases, therefore resulting in the increase in the production costs for the drug preparation.